The creation of brewed or infused beverages through the infusion of a solvent with a solute contained within a filter media has been performed for over one hundred years. Over time it has come to be understood that the modification of brewing variables, such as infusion temperature, pressure, and flow rate of solvent through solute, change the resulting beverage's chemical composition and taste. Thus, many brewing systems have been developed that seek to enable flavor modification through selective modulation of one or more brewing variables. However, few, if any, brewing systems facilitate dynamic, i.e., within the brewing cycle, modulation of one or more of these variables during an infusion. Of those that do, modulation of one or more variables during an infusion results in unintended changes to other brewing variables. This lack of independent variable control makes the optimization and modification of infused beverages difficult.
For instance, currently available brewing systems that enable users to modify pressure during an infusion rely on back pressure generated in a brewing chamber by a resistive media typically composed of a filter and solute. In one configuration, brew chamber pressure modification is achieved by modulating the resistance of said resistive solute media while holding pumping energy constant. While this does result in a change in infusion pressure, it also changes the infusion flow rate. In another conventionally available system, the user modifies infusion pressure through the variation of solvent pumping force while keeping the resistance of the resistive media constant. This too results in an increase in infusion pressure and simultaneous change in infusion flow rate. Thus, in conventional systems, the variables of pressure and flow rate during the infusion process are dependent upon each other. As pressure and flow rate are both known to affect the chemical composition of the brewed infusion, there is an apparent need for a brewing system that affords independent modulation of infusion pressure and flow rate enabling the user to optimize infused solution chemical composition and produce consistent beverages.
Some known devices that are configured to modify one or more brewing variables to provide dynamic pressure control, but, again, lack control over flow rate independent of the pressure control. Specifically, said devices enable the user to create and execute brew formulas which modulate brew pressure and temperature with respect to time. This is performed through the use of a pressure sensor to monitor the infusion pressure within a brew chamber and modulating the pumping force of a water pump such that the desired infusion pressure is achieved in the brew chamber. Temperature control of infusion water is performed by utilizing a proportional mixing valve that is controlled by a controller to mix hot and cold water. While the aforementioned device may be capable of providing dynamic temperature and pressure control, it does so at the expense of the ability to regulate flow rate of the exiting infused beverage. The varying exiting flow rate disadvantageously creates inconsistent beverage output, which is costly for many retailers of beverages. The inconsistencies also are problematic for retailers and consumers, alike, as both the taste of the beverage and the amount of the beverage may change at each brewing cycle. Thus, flow rate, total dispensed volume, and ultimately beverage taste are dependent on variables such as fluctuations in solute particle size, packing density, solute quantity, along with filter media resistivity. As such, this makes it highly difficult to duplicate the flavor of an extraction even if the same brew formula of infusion pressure and temperature with respect to time are used.
It is well understood that infusion temperature also affects chemical composition of an infused beverage solution. Thus, an operator may find it advantageous to modify brewing infusion temperature during the brewing process to optimize flavor. Current brewing systems utilize boilers and brewing chambers with large thermal masses that are designed to provide consistent brewing temperature thus prohibiting the use of variable infusion temperatures to create optimal flavor. Therefore, a beverage brewing system that affords precise, accurate and dynamic temperature control would enable optimization of beverage flavor and is needed.
As previously explained, there is an acute need for a brewing system that affords the brewer independent, dynamic variation of brewing variables of temperature, pressure and flow rate during the production of infused beverages. Furthermore, there is a need for a brewing system that mitigates and/or eliminates the impact of external factors such as solute particle size variations and solute compaction on the beverage flavor.
Furthermore, certain known systems, such as that described in U.S. Pat. No. 8,124,150 (Majer), seek to control flow rate by comparing the actual flow rate downstream of the brewing chamber, utilizing one or more additional sensors, to a predetermined and desired value. As the pressure generated from the compaction and absorption of the solute varies throughout the brewing process, the known systems vary a valve upstream of the brewing chamber to change the flow rate and brew chamber pressure accordingly. This mode of operation is disadvantageous in that those systems require additional sensors that are prone to failure and inaccurate readings. Moreover, these systems require a feedback loop that has its own appreciable disadvantages.
As such, there is also a need solve the above-described disadvantages.